Point-to-multipoint communication system in which automatic ID allocation is possible

ABSTRACT

There is provided a first unit which constitutes a point-to-multipoint communication system and is connected to communicate with each of a plurality of second units. The first unit includes a control signal extraction unit, a signal switching unit and a controller. The control signal extraction unit extracts first control signals respectively transmitted from the plurality of second units. The signal switching unit includes a switching circuit, and selects any one of the first control signals respectively received through individual signal transmission lines. The controller receives the first control signal selected by the signal switching unit, determines an allocation ID to be allocated to a second unit corresponding to the selected first control signal based on the initial identification information of the selected first control signal, and controls the determined allocation ID to be transmitted to the corresponding second unit.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.14/411,484, filed on Dec. 26, 2014, which is a 371 of PCT/KR2014/006531filed on Jul. 18, 2014, and which claims priority from Korean PatentApplication No. 10-2014-0037348, filed on Mar. 29, 2014, in the KoreanIntellectual Property Office, the contents of which are incorporatedherein by reference in their entireties.

TECHNICAL FIELD

The present invention relates to an automatic ID allocation method in apoint-to-multipoint communication system and a point-to-multipointcommunication system using the same.

BACKGROUND ART

Generally, in a point-to-multipoint communication system including adonor unit and a plurality of remote units, a downlink informationsignal and a downlink control signal are transmitted from the donor unitto the plurality of remote units in a broadcasting manner. In thisstate, a unique ID is required for each remote unit for the purpose ofcommunication between the donor unit and the remote unit. When theplurality of remote units simultaneously transmit control signals to thedonor unit in a state in which the unique ID is not allocated to eachremote unit, it is difficult to distinguish between the remote unitsthat have transmitted the control signals, and collision between thecontrol signals may occur.

However, according to a conventional art, in order to allocate a uniqueID to each remote unit, a field worker should allocate, in a directmanual manner, an ID to a corresponding remote unit at an installationposition of the remote unit. For example, there is an inconvenience inthat the field worker should set port #1 of the donor unit and remoteunit #1 one by one so that the port #1 of the donor unit and the remoteunit #1 are connected to each other. In this process, there is a problemthat a setting error occurs, and the like.

SUMMARY

An embodiment of the present invention is directed to an automatic IDallocation method in a point-to-multipoint communication system and apoint-to-multipoint communication system using the same.

According to an aspect of the present invention, a first unit whichconstitutes a point-to-multipoint communication system and is connectedto communicate with each of a plurality of second units, the first unitincludes: a control signal extraction unit configured to extract firstcontrol signals respectively transmitted from the plurality of secondunits, wherein each first control signal includes a unique initialidentification information for each second unit; a signal switching unitconfigured to include a switching circuit, the signal switching unitselecting any one of the first control signals respectively receivedthrough individual signal transmission lines; and a controllerconfigured to receive the first control signal selected by the signalswitching unit, determine an allocation ID to be allocated to a secondunit corresponding to the selected first control signal based on theinitial identification information of the selected first control signal,and control the determined allocation ID to be transmitted to thecorresponding second unit, wherein the allocation ID includesconfiguration information of the corresponding second unit in thepoint-to-multipoint communication system.

The first unit may include a plurality of communication ports providedto correspond to the respective second units, the plurality ofcommunication ports each being connected to each second unit through anindividual signal transmission medium. The configuration information ofthe corresponding second unit to be included in the allocation ID may beinformation on a port connected to the corresponding to the second unitamong the plurality of communication ports. The allocation ID mayinclude the port information and identification information of thecorresponding second unit.

The first control signal may be transmitted together with an uplinkinformation signal transmitted from the second unit to the first unitthrough an uplink signal transmission path. The control signalextraction unit may separate only the first control signal from theuplink information signal received through the uplink signaltransmission path in the first unit and the first control signal, sothat the separated first control signal is transmitted to the signalswitching unit.

The first control signal may be a signal having a frequency banddistinguished from that of the uplink information signal. The controlsignal extraction unit may include a control signal removal unitconfigured to include a band stop filter positioned on the uplink signaltransmission path in the first unit, to remove a signal of a frequencyband corresponding to that of the first control signal from the uplinkinformation signal and the first control signal; and a control signalseparation unit disposed prior to an input terminal of the band stopfilter based on an uplink signal transmission direction, the controlsignal separation unit including a band pass filter positioned on asignal branch path branched from the uplink signal transmission path inthe first unit, to pass a signal of a frequency band corresponding tothat of the first control signal from the uplink information signal andthe first control signal.

Individual uplink signal transmission paths corresponding to therespective second units may be formed in the first unit. The controlsignal extraction unit may be disposed on each uplink signaltransmission path corresponding to each second unit. The signalswitching unit may receive a plurality of first control signalstransmitted from the plurality of control signal extraction unitsdisposed on the respective uplink signal transmission paths throughdifferent signal branch paths.

The signal switching unit may include switches respectively disposed onthe different signal branch paths where the plurality of first controlsignals are received. The controller may control operations of aplurality of switches provided in the signal switching unit, to allowonly any one of the plurality of switches to be switched on, therebyselecting only any one of the plurality of first control signalsreceived from the plurality of second units.

The controller may determine an allocation ID to be mapped to eachsecond unit in such a manner that the operation of the plurality ofswitches are sequentially switched on, and control the determinedallocation ID to be transmitted to each second unit along a downlinksignal transmission path provided for each second unit.

The allocation ID may be included in a downlink information signal or adownlink control signal to be transmitted to the corresponding secondunit.

According to another aspect of the present invention, apoint-to-multipoint communication system including the first unit and aplurality of second units connected to communicate with the first unit,the point-to-multipoint communication system wherein each second unitincludes a controller, when an allocation ID is transmitted from thefirst unit, configured to register the transmitted allocation ID,generate a second control signal including the registered allocation ID,and control the second control signal to be transmitted together with anuplink information signal to the first unit through an uplink signaltransmission path.

In initial setting of a signal transmission path between the second unitand the first unit, the controller of the second unit may generate thefirst control signal including unique initial identification informationof the second unit, and control the first control signal to betransmitted to the first unit through the signal transmission path.

The second control signal may be generated as a signal of a frequencyband equal to that of the first control signal. When an allocation ID istransmitted to each second unit or when the second control signal isreceived, the controller of the first unit may control the operation ofthe signal switching unit so that a plurality of second control signalsrespectively received from the plurality of second units pass throughthe different signal branch paths and then are again transmitted throughthe uplink signal transmission path.

According to the present invention, in the point-to-multipointcommunication system such as a distributed antenna system, automatic IDallocation is possible in such a manner that separates and switches acontrol signal transmitted for each remote unit, so that it is possibleto reduce time and errors, caused in directly setting an ID for eachremote unit when the remote unit is initially installed. Further,although the port position of an equipment is changed, theidentification of a remote unit can be automatically performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an embodiment of a distributed antennasystem including a donor unit and a plurality of remote units, as anexample of a point-to-multipoint communication system.

FIG. 2 is a diagram illustrating a point-to-multipoint communicationsystem in which automatic ID allocation is possible according to anembodiment of the present invention.

FIG. 3 is a block diagram illustrating a control signal extraction unitin FIG. 2.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention will be described belowin more detail with reference to the accompanying drawings. The presentinvention may, however, be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the present invention tothose skilled in the art. Throughout the disclosure, like referencenumerals refer to like parts throughout the various figures andembodiments of the present invention.

Throughout the description of the present invention, when describing acertain technology is determined to evade the point of the presentinvention, the pertinent detailed description will be omitted. Numerals(e.g., first, second, etc.) used in the description of the presentinvention are only for distinguishing one element from another element.

When one element is described as being “connected” or “accessed” toanother element, it shall be construed as being connected or accessed tothe other element directly but also as possibly having another elementin between. On the other hand, if one element is described as being“directly connected” or “directly accessed” to another element, it shallbe construed that there is no other element in between.

FIG. 1 is a diagram illustrating an embodiment of a distributed antennasystem including a donor unit and a plurality of remote units, as anexample of a point-to-multipoint communication system. FIG. 2 is adiagram illustrating a point-to-multipoint communication system in whichautomatic ID allocation is possible according to an embodiment of thepresent invention. FIG. 3 is a block diagram illustrating a controlsignal extraction unit in FIG. 2.

In the point-to-multipoint communication system according to theembodiment of the present invention, when being compared with FIG. 1, acontrol signal extraction unit 120 and a signal switching unit 130 arefurther provided in a donor unit 100 in order to perform automatic IDallocation on each remote unit. In this state, a controller 150 of thedonor unit 100 and controllers (see 250-1 and 250-N) of the respectiveremote units (see 200-1 and 200-N) have a predetermined function forperforming automatic ID allocation. That is, FIG. 2 illustrates that aconfiguration and a function for performing automatic ID allocation foreach remote unit according to the embodiment of the present inventionare further added based on the configuration of an example of thepoint-to-multipoint communication system as shown in FIG. 1. Thus, it isobvious that, when the basic configuration and structure of thepoint-to-multipoint communication system is different from those of FIG.1, the embodiment of the present invention will also be changed suitablefor the different configuration and structure of the point-to-multipointcommunication system. Therefore, it will be apparent that, if the keyfunction and configuration of the present invention, which will bedescribed below, are included, the present invention is not necessarilylimited to the structure and configuration of FIG. 2.

In this specification, a method will be described which automaticallyallocates an ID to each remote unit in a case where a plurality ofremote units are connected to one donor unit in a point-to-multipointmanner based on FIG. 2. However, the present invention may besubstantially equally applied to even a case where another plurality ofremote units are connected to one remote unit in the point-to-multipointmanner according to an embodiment.

Referring to FIG. 2, the donor unit 100 is individually connected to Nremote units 200-1 to 200-N through different ports. The donor unit 100and the N remote units 200-1 to 200-N are connected through atransmission medium. Here, the transmission medium is not necessarilylimited to a wired medium (a twist pair cable, a coaxial cable, an opticfiber, or the like), and may be a wireless medium. In this state, asignal conversion unit of the donor unit 100 and signal conversion unitsof the respective remote units 200-1 to 200-N perform signal conversionaccording to the transmission medium. For example, when the transmissionmedium is an optic fiber, the signal conversion unit may include aconfiguration for electro-optic conversion and optic-electro conversion.

In order to implement the point-to-multipoint communication system, whenthe donor unit 100 and the N remote units 200-1 to 200N are initiallyconnected for each port, each remote controller 250-1 to 250-Nindividually provided in each remote unit 200-1 to 200-N generates afirst control signal and transmits the generated first control signal tothe donor unit 100. Here, unique initial identification information(e.g., the MAC address of a corresponding equipment, an initially setID, etc.) for each remote unit may be included in the first controlsignal. According to an embodiment, the first signal may be combinedtogether with an uplink information signal transmitted from each remoteunit, to be transmitted to the donor unit through a predetermined uplinksignal transmission path.

If the uplink information signal and the first control signal aretransmitted to the donor unit 100, the control signal extraction unit120 of the donor unit 100 separates only the first control signal fromthe uplink information signal and the first control signal. Aconfiguration example of the control signal extraction unit 120 isillustrated in FIG. 3. Referring to FIG. 3, the control signalextraction unit 120 includes a control signal separation unit 122 and acontrol signal removal unit 124. Here, the control signal removal unit124 is positioned on an uplink signal transmission path (seeidentification symbol (a) of FIG. 3), and performs a function ofremoving the first control signal from the uplink information signal andthe first control signal, transmitted along the uplink signaltransmission path (a). To this end, the control signal removal unit 124may include a band stop filter for removing a signal of a frequency bandcorresponding to that of the first control signal. The control signalseparation unit 122 is disposed prior to the control signal removal unit124 based on an uplink signal transmission direction. The control signalseparation unit 122 is positioned on a signal branch path (seeidentification symbol (b) of FIG. 3) branched from the uplink signaltransmission path (a), and performs a function of separating only thefirst control signal from the uplink information signal and the firstcontrol signal. To this end, the control signal separation unit 122 mayinclude a band pass filter for passing only a signal of a frequency bandcorresponding to that of the first control signal. In order to performthe separation and removal of only the first control signal, the firstcontrol signal may have a frequency band distinguished from that of theuplink information signal. However, the configuration example of FIG. 3is merely an example, and may be variously modified within the limitwhere the substantially same function is performed.

The control signal extraction unit 120 described above is provided on anuplink signal transmission path for each port, and each control signalextraction unit 120 is connected to the signal switching unit 130through an individual signal transmission line. Accordingly, each firstcontrol signal transmitted from each remote unit 200-1 to 200-N can betransmitted to the signal switching unit 130 via each control signalextraction unit 120.

The signal switching unit 130 includes switching circuits, to select anyone of the first control signals received through the respectiveindividual signal branch paths. For example, the signal switching unit130 may include switches disposed on the respective individual signalbranch paths, and the controller 150 may allow any one of the pluralityof switches provided in the signal switching unit 130 to be switched onby controlling operations of the plurality of switches, therebyselecting only a specific first control signal.

As described above, when only a specific first control signal isselected, the controller 150 receives the selected first control signaland determines an allocation ID to be allocated (mapped) to a remoteunit corresponding thereto (i.e., the remote unit that has transmittedthe selected first control signal) based on initial identificationinformation included in the received first control signal. Here,configuration information that enables the configuration position of acorresponding remote unit in the point-to-multipoint communicationsystem, and the like to be identified may be included in the allocationID. As an example, information on a port to which a corresponding remoteunit is connected may be used as the configuration information. That is,in the automatic allocation of an ID to the identified remote unit, thecontroller 150 may use a new ID obtained by combining port informationand information capable of identifying the corresponding remote unit(the information may be the initial individual information, but may beidentification information newly selected in a mapping process, e.g.,information on a name to be newly provided).

The allocation ID newly defined as described above is again transmittedto the corresponding remote unit through the original downlink signaltransmission path by control of the controller 150. In this state, thenew allocation ID may be included a downlink information signal or adownlink control signal, to be transmitted to the corresponding remoteunit. Accordingly, the controller (250-1 or 250-N of FIG. 2) of thecorresponding remote unit registers the transmitted allocation ID. In asubsequent communication process, the remote unit performs communicationwith the donor unit using the newly registered allocation ID. Forexample, the remote unit may generate a second control signal includingthe registered allocation ID and use the generated second signal in asubsequent communication process. In this state, the second controlsignal may have a frequency band equal to that of the first controlsignal.

The automatic ID allocation process described above is performed on allthe remote units. To this end, the controller 150 of the donor unit 100may determine, in such a manner that a plurality of switches aresequentially switched on one by one, an allocation ID for each remoteunit corresponding to each switch, and control the determined allocationID to be transmitted to each remote unit.

As described above, according to the embodiment of the presentinvention, in the point-to-multipoint communication system, an ID can beautomatically allocated for each remote unit without relying on IDallocation in a manual manner of a field worker. Also, according to theembodiment of the present invention, when there occurs a change inconfiguration, including replacement, addition or the like of anequipment, an ID can be automatically allocated according to the change.After the automatic ID allocation is completed as described above (orwhen the second control signal is received from the remote unit), thecontroller 150 of the donor unit 100 may control the operation of thesignal switching unit 130 so that all the second control signalsreceived from the respective remote units can be normally transmittedthrough the uplink signal transmission paths. This is because, after theinitial setting is completed, all the second control signals transmittedfrom the respective remote units are to be transmitted in the directionof a network management system (NMS).

While the present invention has been described with respect to thespecific embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

The invention claimed is:
 1. A first unit which constitutes acommunication system and is connected to communicate with each of aplurality of second units, the first unit comprising: a memory to storeinstructions; and a processor, coupled to the memory, to facilitateexecution of the instructions to perform operations, comprising:extracting first control signals respectively transmitted from theplurality of second units, wherein each first control signal includes aunique initial identification information for each second unit;selecting any one of the first control signals respectively receivedthrough individual signal transmission media; determining an allocationID to be allocated to a second unit corresponding to the selected firstcontrol signal based on the unique initial identification information ofthe selected first control signal; transmitting the determinedallocation ID to the second unit so that the second unit registers thedetermined allocation ID and generates a second control signal includingthe registered allocation ID; and receiving the second control signalfrom the second unit among the plurality of second units based on theallocation ID, wherein the allocation ID includes configurationinformation of the second unit in the communication system.
 2. The firstunit of claim 1, wherein the first unit includes a plurality ofcommunication ports provided to correspond to the respective secondunits, the plurality of communication ports each being connected to eachsecond unit through the individual signal transmission media, whereinthe configuration information of the second unit to be included in theallocation ID is information on a port corresponding to the second unitamong the plurality of communication ports, and wherein the allocationID includes the port information and identification information of thesecond unit.
 3. The first unit of claim 2, wherein the second unittransmits an uplink signal including the first control signal and anuplink information signal to the first unit through an uplink signaltransmission path, and wherein the operations further compriseseparating only the first control signal from the uplink signal receivedthrough the uplink signal transmission path in the first unit.
 4. Thefirst unit of claim 3, wherein the first control signal is a signalhaving a frequency band distinguished from that of the uplinkinformation signal, and wherein the operations further compriseseparating a signal of a frequency band corresponding to the firstcontrol signal from the uplink signal.
 5. The first unit of claim 1,wherein the operations further comprise: determining an allocation ID tobe mapped to each second unit; and transmitting the determinedallocation ID to each second unit along a downlink signal transmissionpath provided for each second unit.
 6. The first unit of claim 1,wherein the allocation ID is included in a downlink information signalor a downlink control signal to be transmitted to the second unit.
 7. Acommunication system comprising the first unit of claim 1 and aplurality of second units connected to communicate with the first unit,each second unit comprising: a memory to store instructions; and aprocessor, coupled to the memory, to facilitate execution of theinstructions to perform operations, comprising: registering atransmitted allocation ID transmitted from the first unit; generating asecond control signal including the registered allocation ID; andtransmitting the second control signal together with an uplinkinformation signal to the first unit through an uplink signaltransmission path.
 8. The communication system of claim 7, wherein theoperation further comprise: generating the first control signalincluding unique initial identification information of the second unit;and transmitting the first control signal to the first unit through thesignal transmission path.
 9. The communication system of claim 7,wherein the operation further comprise: generating the second controlsignal as a signal of a frequency band equal to the first controlsignal.
 10. A method for operating of a first unit which constitutes acommunication system and is connected to communicate with each of aplurality of second units, the method comprising: extracting firstcontrol signals respectively transmitted from the plurality of secondunits, wherein each first control signal includes a unique initialidentification information for each second unit; selecting any one ofthe first control signals respectively received through individualsignal transmission media; determining an allocation ID to be allocatedto a second unit corresponding to the selected first control signalbased on the unique initial identification information of the selectedfirst control signal; transmitting the determined allocation ID to thesecond unit so that the second unit registers the determined allocationID and generates a second control signal including the registeredallocation ID; and receiving the second control signal from the secondunit among the plurality of second units based on the allocation ID,wherein the allocation ID includes configuration information of thesecond unit in the communication system.
 11. The method of claim 10,wherein the first unit includes a plurality of communication portsprovided to correspond to the respective second units, the plurality ofcommunication ports each being connected to each second unit through theindividual signal transmission media, wherein the configurationinformation of the second unit to be included in the allocation ID isinformation on a port corresponding to the second unit among theplurality of communication ports, and wherein the allocation ID includesthe port information and identification information of the second unit.12. The method of claim 11, wherein the second unit transmits an uplinksignal including the first control signal and an uplink informationsignal to the first unit through an uplink signal transmission path, andwherein the method further comprises separating only the first controlsignal from the uplink signal received through the uplink signaltransmission path in the first unit.
 13. The method of claim 12, whereinthe first control signal is a signal having a frequency banddistinguished from that of the uplink information signal, and whereinthe method further comprises separating a signal of a frequency bandcorresponding to that of the first control signal from the uplinksignal.
 14. The method of claim 10, further comprises: determining anallocation ID to be mapped to each second unit; and transmitting thedetermined allocation ID to each second unit along a downlink signaltransmission path provided for each second unit.
 15. The method of claim10, wherein the allocation ID is included in a downlink informationsignal or a downlink control signal to be transmitted to the secondunit.